The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
The present invention relates generally to airborne fire fighting systems and methods, and more particularly to an improved system and method for pressurizing and dispersing fire retardant from an aircraft equipped for retarding or extinguishing forest fires.
Aircraft such as the C-130 presently used for fire fighting by agencies such as the U.S. Forest Service are outfitted with liquid fire retardant dispersal systems including a liquid retardant reservoir, compressed air tanks, air compressor, discharge tube and nozzles, and related equipment all mounted on movable pallets. The systems are designed to perform multiple individual discharges each of several hundred gallons over a 4 to 5 second period, in a single flight, or to discharge the entire contents in a single burst. The systems are generally large and heavy, have power requirements that severely tax the available power supply aboard an aircraft, and potential electromagnetic interference (EMI) from the equipment that can be disruptive to the aircraft avionics.
The invention solves or substantially reduces in critical importance problems with previously existing aircraft based fire retardant dispersal systems by providing a system including a small light weight power pack having a plenum operatively connecting a plurality of individual solid propellant gas generator devices each containing solid propellant materials that react pyrotechnically when initiated electrically to generate large quantities of high-pressure gas in a few seconds for providing the force required to discharge the liquid fire retardant from a reservoir. The gas generator devices require negligible power to kick start and do not produce significant EMI. The invention may be applied to substantially any system for pressurizing and dispersing fire retardant from an airborne fire fighting aircraft currently used or contemplated for use. The space and weight savings afforded by use of the invention over conventional systems are substantial (about 800 lbs to 50 lbs weight reduction and about 36 cubic feet to about 1 cubic foot). The gas generator devices are sufficiently inexpensive as to afford replacement after each flight.
It is therefore a principal object of the invention to provide an improved system for retarding or extinguishing ground fires such as forest fires.
It is another principal object of the invention to provide an improved airborne fire fighting system.
It is another object of the invention provide an improved airborne fire fighting system for pressurizing and dispersing liquid fire retardant from substantially any type of aircraft.
It is a further object of the invention to provide a lightweight airborne fire fighting system having small size and improved operational characteristics.
These and other objects of the invention will become apparent as a detailed description of representative embodiments proceeds.
In accordance with the foregoing principles and objects of the invention, system and method are provided for pressurizing and dispersing fire retardant from an aircraft, particularly aircraft structured and equipped for retarding or extinguishing forest fires, that includes a small power pack having a plenum operatively interconnecting a plurality of individual solid propellant gas generator devices each containing solid propellant materials that react pyrotechnically when initiated electrically to generate large quantities of high-pressure gas in a few seconds for discharging a liquid retardant reservoir.